Sanitary fitting for thermometer bulbs



Jan. 30, 1940. A. NOBLE SANITARY FITTING FOR THERMOMETER BULBS Filed Dec. 15, 1938 2 Sheets-Sheet 1 INVENTOR. AL PHO/VSO /V0BL ATTORNEY.

Jan. 30, 1940. A. NOBLE SANITARY FITTING FOB THERMOMETER BULBS Filed Dec. 15, 1938 2 Sheets-Sheet 2 INVENTOR. ALPHO/VSO #0515 /fiauflw ATTORNEY.

Patented Jan. 30, 1940 UNITED. STATES PATENT OFFlCE Alphonso Noble, Naugatuck, Conn., assignor to The Bristol Company, Waterbury, Conn., a corporation of Connecticut Application December 15,

1938, Serial No. 245,884"

3 Claims. (Cl. 285-177) This invention relates to a fitting or mounting for thermometer bulbs, and more especially to a readily releasable and replaceable fitting of the above nature suitable for use in dairies and other places where sanitary features are of paramount importance.

The extreme cleanliness demandedof equipment used in modern dairy practice requires that all parts of equipment coming in contact with milk being processed not only presentno crevices or intersticeswherein foreign matter may lodge, but that they be subject to easy and rapid disassembly for cleaning and sterilization," and. to equally easy re-assembly for service.

With the above requirements in view, it has been customary to provide the bulbs of record-' ing and controlling thermometers used in'dairy work with threaded fittings. in' the forms of unions or stufiing boxes which may readily be sterilized when dismantled. Such a device is shown in U. S. Letters Patent No. 1,828,170 issued to C. W. Bristol October 20, 1931, and embodies a metallic fitting adapted to retain a thermometer bulb in operating position, and'to be releasable by the unscrewing of a single thumb nut.

It is an object of the present invention to provide an improved fitting of the above general nature, in which the complete clamping may be efiected'by a partial turn'of a rotatable clamping member without the possibility of over-tightening, and which fitting may be similarly released.

A further object of the invention is found in the' provision of a device of the above nature in which sanitation is facilitated by the absence of irregular projecting parts or crevices.

A still further object is found in the provision of such a device in which a leak-proof assembly is not dependent upon'the engagement of highlyfinished metallic parts.

In carrying out the invention, a ferrule and a clamping element are provided and designed to fit over the thermometer bulb, each being provided with a, cylindrical bore having at the inner end a conical tapered section, and the clamping element being adapted to be inserted into the bore of the ferrule and to be locked thereto to hold and compress between the said tapered sections a washer of resilient material for providing a liquid-tight engagement with all the surface it touches.

The nature of the invention, however, will best be understood when described in connection with the accompanying drawings, in which:

Fig. 1 is a front elevation, partly in longitudinal section, ofa fitting'embodyin'g the invention and assembled with a thermometer bulb in place. Figs. 2 to 4, inclusive, are views, in side elevation, showing the various elements of the novel fitting, Fig. 2 showing the clamping element and v Fig. 4 the ferrule thereof, while Fig. 3 shows a resilient washer held between the said ferrule and clamping element.

Fig. 5 is, a front elevation, partly in longitudinal section, illustrating a modification;

Fig. 6 isa similar view of a further modification; and Figs. 7 and 8 are, respectively, a fragmentary plan view and a fragmentary side elevation and longitudinal sectionthereof. I

Referring to the drawings, Ill designates a thermometer bulb of the conventional form used in dairies, and consists of a hollow'cylindrical metallic closed casing containing an expansible or volatile fluid. This casing is connected by means of a capillary tube II to a pressure-responsive member (not shown in the drawings, but well known in the art of temperature measthe, fluid contained within the bulb I0, due to changes in temperature of the fluid in which the bulb is immersed, may be. utilized to provide ameasure-of, or tocommand an automatic control of, the, said temperature.

A ferrule member I2 is provided with a conical face 13 adapted to fit, a suitably formed face of a standard dairy fitting (not shown in the drawings) and the said ferrule is adapted to be clamped to the standard fitting by means of a nut II to form therewith a sanitary union of a type well known in dairy practice and forming no part of the present invention. Formed within the ferrule member I2 is a cylindrical recess l5 of a diameter materially greater than that of the bulb I0, and provided at its inner end with a sonically tapered section l6 leading to a featheredged aperture I6 having a diameter substantially equal to that of the bulb I0. Toward the outer end of the recess 15 are formed in they material of the ferrule l2 diametrically opposed slots I l, directed at first axially, then curving to a circumferential direction, and attaining a slightly hook-shaped conformation, as shown in Fig. 1. v

A clamping member or gland 18 has its one extremity in the form. of a wing-nut, and is of an outer cylindrical surface having a diameter such as to provide a free-running fit within the recess 15 in the ferrule 12. A cylindrical bore I 8 therethrough is made of a diameter to provide a sliding fit on the bulb l0; and, at the extremity opurement) and whereby variations in pressure of i posed to that having the wing-nut conformation, there is provided a conically tapered recess l9 similar in dimensions to those of the tapered section l6 within the ferrule I2 and adapted to be juxtaposed to the section I6. Diametrically opposed on the outer surface of the cylindrical part of the member l8 are disposed outwardly projecting pins 20 adapted to enter the slots II when the clamping member I8 is inserted Within the ferrule l2; and, as the two members are relatively rotated, the said pins engage the circumferential parts of said slots, forming therewith a bayonet joint and drawing the said members together in clamping engagement. Of course, the arrangement of pins and slots may be the reverse,

the latter then being provided in the gland IS- with the cooperating pins projecting from the ferrule l2.

A washer 2 I, shown in Fig. 3, is formed of resilient material, such as neoprene, cork, or paraffined paper, not subject to ready attack or contamination by milk, with opposed conical surfaces adapted to be engaged by the corresponding surfaces I6 and I9, respectively, of the ferrule and the clamping member. This washer, also, is provided with a central opening 22 designed to fit closely the cylindrical surface of the bulb 10, sothat when the washer is placed upon the bulb and clamped between the said conical surfaces of the ferrule and the gland respectively, it will be compressed into said liquid-tight engagement with all surfaces which it contacts and will provide a secure fastening for the bulb without exposing any appreciable surface-to contact with the milk in which the bulb may be immersed. The feather edge l6 to which the section I6 is reduced eliminates the possibility of lodgement of foreign matter at this point in the assembly. As these washers are obtainable at a relatively low cost, they may be economically discarded after once being used.

In the modification illustrated in Fig. 5, a gland member 25 bears upon a similar washer 28 to press the same against the bulb 21 and a feather edge 28 of a ferrule 29, this being accomplished by providing the latter with an external thread 30 engaged by the internal thread of a sleeve 3| depending from a clamping member 32 separate from the gland 25. The said clamping member is rotatably mounted upon the bulb 21, being manipulated by the integral wings 33, and has an inner shoulder 34 to engage the gland 25 and press it into contact with washer 26.

Or, as indicated in Figs. 6 to 8, inclusive, the separate clamping member 35 may be wedged against the gland 36 through engagement of headed pins or studs 31 extending upwardly from the ferrule 38 and diametrically disposed on the top of said ferrule. The studs pass into corresponding and diametrically disposed keyhole slots 39 of the clamping member and having a sloping surface 40, adapted for engagement with the respective heads of studs 3'! as the clamping member is correspondingly rotated. By this expedient, the gland 36 is accordingly advanced to exert pressure upon the washer M, or this pressure is released for disassembling the fitting.

I claim:

1. Means for mounting a thermometer bulb having contact with a liquid, said means including a pair of bored coaxial clamping members surrounding a portion of the bulb, one member fitting slidably within the other and engaged therewith by a clamping joint to slide axially the one member relatively to the other, and the bores of both members affording respective juxtaposed opposed recesses, together with a resilient Washer located within the said recesses, adapted to be clamped between said members and thereby forced into liquid-tight engagement with the surface of said bulb.

2. Means for mounting a thermometer bulb having contact with a liquid, said means including. a pair of bored coaxial clamping members surrounding a portion of the bulb, one member fitting slidably within the other and engaged therewith by a clamping joint to slide axially the one member relatively to the other, and the bores of both members affording respective juxtaposed opposed conical recesses with the recess of the innermost member tapering to a feather edge having a diameter providing a sliding fit for said bulb, together with a resilient washer located within the'said recesses, adapted to be clamped between said members and thereby forced into liquid-tight engagement with the surface of said bulb and the feather edge.

3. Means for mounting a cylindrical thermometer bulb in contact with a liquid, including clamping members surrounding said bulb and having therein opposed recesses disposed coaxially with said bulb, said members forming a stuffing box adapted in response to clamping forces to exert centrally directed radial forces on the contents of the stuffing box, together with a washer of resilient material located between said clamping members about the bulb with opposite faces in contact with the respective walls of said recesses and to be clamped into intimate engagement with the cylindrical surface of said bulb, and means to slide the one clamping member axially relatively to the other and including a manually operable element mounted over the bulb and in threaded engagement with the other clamping member- ALPHONSO NOBLE. 

